Heat dissipation module

ABSTRACT

A heat dissipation module suitable for an electronic device is provided. The electronic device has a heat source. The heat dissipation module includes an evaporator and a pipe assembly. An internal space of the evaporator is divided into a first space and a second space, and the heat source is thermally contacted with the second space. The pipe assembly is connected to the evaporator to form a loop. A working fluid is filled in the loop. The working fluid in liquid receiving heat from the heat source is transformed into vapor and flows to the pipe assembly. Then, the working fluid in vapor is transformed into liquid by dissipating heat in the pipe assembly and flows to the first space of the evaporator. The working fluid in liquid is stored in the first space and is used for supplying to the second space.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Taiwan applicationserial no. 105102477, filed on Jan. 27, 2016, and Taiwan applicationserial no. 104122924, filed on Jul. 15, 2015. The entirety of each ofthe above-mentioned patent applications is hereby incorporated byreference herein and made a part of this specification.

BACKGROUND

1. Technical Field

The disclosure relates to a heat dissipation module.

2. Description of Related Art

As the industries of science and technology continuously advance inrecent years, electronic devices, such as notebook computers, personaldigital assistants (PDAs), and smart phones, are used more and morefrequently in our daily life. Some electronic elements in the electronicdevices may generate heat when they are operating, and the generatedheat may influence the performance of the electronic devices. Therefore,it is common to dispose a heat dissipation module or a heat dissipationmember, such as a heat dissipation fan, a heat dissipation adhesivematerial, or a heat dissipation pipe, in the electronic device so as todissipate the heat generated by the electronic elements outside theelectronic devices.

Among the heat dissipation modules, the heat dissipation fan is capableof effectively dissipating heat outside, but it consumes a significantamount of power, and is heavier and requires more space. Therefore, itis less preferable to install the heat dissipation fan in an electronicdevice pursuing a thinner and a lighter design. Besides, the heatdissipation fan may generate noise that influences the communicationfunction provided by the electronic device. Furthermore, to allow theheat dissipation fan to dissipate heat through convection, the case ofthe electronic device needs to provide an opening, but providing anopening may reduce the mechanical strength of the electronic device.

As for the heat dissipation adhesive material, such material may absorbthe heat of the electronic elements and reduce surface temperature. Inaddition, the cost and space requirements of the heat dissipationadhesive material are lower, so the heat dissipation adhesive materialcan be broadly used in the electronic device. However, it is difficultfor the heat dissipation adhesive material to further dissipate the heatoutside via other components, so the heat dissipation effect of the heatdissipation adhesive material is limited.

The heat dissipation pipe is able to transfer the heat of the electronicelements to another plate element. However, due to lack of convection,the heat dissipation effect of the heat dissipation pipe is limited.Accordingly, the heat dissipation pipe may be used with an evaporatorand a condenser to form a loop, and a transformable heat transferringmedium capable of transforming between two phases (e.g., liquid phaseand vapor phase) by absorbing or releasing heat may circulate in theheat dissipation pipe to absorb heat in the evaporator and release heatin the condenser, thereby transferring the heat from the electronicelements to the outside. Nevertheless, the heat transferring medium onlycirculates in the loop through its own transformation, so the effect ofcirculation is less desirable. Thus, the effect of heat dissipation ofthe heat transferring medium is limited.

SUMMARY

The disclosure provides a heat dissipation module providing a preferableflowing efficiency and heat dissipation effect when a working fluidflows in a loop formed by an evaporator and a pipe assembly.

A heat dissipation module according to an embodiment of the disclosureis suitable for an electronic device is provided. The electronic devicehas a heat source. The heat dissipation module includes an evaporatorand a pipe assembly. An internal space of the evaporator is divided intoa first space and a second space, and the heat source is thermallycontacted with the second space. The pipe assembly is connected to theevaporator to form a loop. A working fluid is filled in the loop. Theworking fluid in liquid receiving heat from the heat source transformsinto the working fluid in vapor and flows to the pipe assembly. Then,the working fluid in vapor transforms into the working fluid in liquidby dissipating heat in the pipe assembly and flows to the first space ofthe evaporator. The working fluid in liquid is stored in the first spaceand is used for supplying to the second space.

Based on the above, in the heat dissipation module, the evaporator andthe pipe assembly are combined to form the closed loop, and the workingfluid is filled into the loop, so that the heat is absorbed anddissipated through transformation of the working fluid.

The cavity of the evaporator is divided into the first space and thesecond space. The heat source is only in thermal contact with the secondspace, so only the working fluid in liquid in the second space istransformed due to absorption of heat, and the first space may stillstore the working fluid in liquid, so as to guide and supply the workingfluid in liquid to the second space for heat absorption.

In order to make the aforementioned and other features and advantages ofthe invention comprehensible, several exemplary embodiments accompaniedwith figures are described in detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention.

FIG. 1 is a schematic view illustrating that a heat dissipation moduleaccording to an embodiment of the invention is applied in an electronicdevice.

FIG. 2 is an exploded view of the heat dissipation module of FIG. 1.

FIG. 3 is a partial top view illustrating a heat dissipation moduleaccording to another embodiment of the invention.

FIG. 4 is a partial side view illustrating the heat dissipation moduleof FIG. 3.

FIG. 5 is a schematic view illustrating a part of components of the heatdissipation module of FIG. 2.

FIG. 6 is a schematic partial view illustrating a heat dissipationmodule according to another embodiment of the invention.

FIG. 7 is a partial schematic cross-sectional view illustrating a heatdissipation module according to yet another embodiment of the invention.

FIGS. 8 and 9 are respectively exploded views illustrating an evaporatoraccording to still another embodiment of the invention.

FIG. 10 is a perspective view illustrating the evaporator of FIGS. 8 and9.

FIG. 11 is a cross-sectional view illustrating the evaporator of FIG. 10along an A-A′ line.

DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the present preferredembodiments of the invention, examples of which are illustrated in theaccompanying drawings. Wherever possible, the same reference numbers areused in the drawings and the description to refer to the same or likeparts.

FIG. 1 is a schematic view illustrating that a heat dissipation moduleaccording to an embodiment of the invention is applied in an electronicdevice. Here, only a part of the electronic device is shown for anillustrative purpose. In addition, Cartesian coordinates are provided inFIG. 1 as well as subsequent drawings for the convenience of identifyingdirections of components. FIG. 2 is an exploded view of the heatdissipation module of FIG. 1. Referring to FIGS. 1 and 2, in thisembodiment, a heat dissipation module 100 is suitable for an electronicdevice, such as a mobile electronic device like a notebook computer.Here, a case 10 of the electronic device is shown for an illustrativepurpose. The heat dissipation module 100 is disposed in the case 10, andtransfers heat generated by electronic elements in the electronic deviceto the case 10 to be dissipated by utilizing a thermal contact effect ofthe structure, thereby dissipating the heat. Further details in thisregard will be described in the following.

The electronic device has a heat source 20. The heat source 20 may be aprocessor or a display chip, for example, that is disposed on a circuitboard 21. The heat dissipation module 100 includes an evaporator 110 anda pipe assembly 120. The evaporator 110 has an inlet E1 and an outletE2. Two opposite ends of the pipe assembly 120 are connected to theinlet E1 and the outlet E2 to form a closed loop with the evaporator110. A working fluid F is filled in the loop, such that heat is absorbedand dissipated through phase transformation of the working fluid F.Here, an arrow sign is used to indicate a flow direction of the workingfluid F.

In this embodiment, the heat dissipation module 100 further includes aheat pipe 130, heat dissipation members 140 and 150, heat conductivepads 160, and a pressing member 170. The pressing member 170 isconfigured to lock the heat dissipation member 140 and the circuit board21 together. The heat pipe 130 is disposed on the pressing member 170and the heat dissipation member 140, so that one end of the heat pipe130 is thermally contacted with the heat source 20, and the other end ofthe heat pipe 130 is connected to the evaporator 110. Accordingly, heatgenerated by the heat source 20 may be transferred to the evaporator 110through the heat pipe 130.

Specifically, after the heat from the heat pipe 130 is transferred tothe evaporator 110, the working fluid F therein is heated andtransformed (e.g., from a liquid phase to a vapor phase), and flows inthe loop. Once the working fluid F passes through a position where thepipe assembly 120 and the heat dissipation member 140 are connected, theworking fluid F may be transferred to the heat dissipation member 140utilizing the heat. Namely, the heat dissipation member 140 may beconsidered as a condensing end of the loop that transforms the workingfluid F again (e.g., from the vapor phase to the liquid phase), so thatthe working fluid F may flow back to the evaporator 110 along the loop.Accordingly, by circulative transformation of the working fluid F in theloop, the evaporator 110 and the pipe assembly 120 are able to absorband dissipate heat. Moreover, the heat dissipation member 150 is stackedon the heat dissipation member 140 and come into contact with the case10 through a plurality of the heat conductive pads 160. Accordingly, theheat dissipation members 140 and 150 are able to absorb heat from thepipe assembly 120 and transfer the heat to the case 10 through the heatconductive pads 160. Consequently, the heat may be eventually dissipatedout of the electronic device.

FIG. 3 is a partial top view illustrating a heat dissipation moduleaccording to another embodiment of the invention. FIG. 4 is a partialside view illustrating the heat dissipation module of FIG. 3. Referringto FIGS. 3 and 4, what differs from the previous embodiment is that apipe assembly 220 of a heat dissipation module 200 of this embodimentsubstantially surrounds an input assembly 11. More specifically, theinput assembly 11 has an element 11 a, such as a support member of atouch pad or a keyboard module, and the element 11 a is formed of athermally conductive material (e.g., metal). Therefore, by having thepipe assembly 220 thermally contact the element 11 a, the heat may betransferred to the element 11 a to be dissipated out of the electronicdevice. Namely, the working fluid F in the loop substantially absorbsthe heat from the heat source 20 at the evaporator 210, and then theheat is dissipated by having the pipe assembly 220 thermally contact theelement 11 a.

Similar to the previous embodiment, the heat source 20 transfers theheat to the evaporator 210 through the heat pipe 130. However, theinvention does not intend to impose a limitation as to how the heat istransferred. In another embodiment not shown herein, the heat source maydirectly and physically contact the evaporator.

Based on the above, the heat dissipation modules 100 and 200 accordingto the embodiments of the invention are able to employ a structuralmember or an appearance member of the electronic device as a medium todissipate the heat.

FIG. 5 is a schematic view illustrating a part of components of the heatdissipation module of FIG. 2. Referring to FIG. 5, in this embodiment,the evaporator 110 includes a base 112, an upper cover 114, and aplurality of heat conductive pillars 116. In addition, the base 112 andthe upper cover 114 are combined to form a cavity, such that the workingfluid F may flow and undergoes transformation in the cavity. It shouldbe noted that, using a virtual plane P1 (which may be considered as anX-Y plane or a plane parallel to the X-Y plane) where the base 112 islocated as reference, there is a height difference between the inlet E1and the outlet E2 of the evaporator 110. Namely, there a differencealong a Z-axis.

More specifically, the internal cavity of the evaporator 110 may besubstantially divided into a second space (evaporation space) A2 and afirst space (supply space) A1. In addition, there is a height differenceΔZ between the first space A1 and the second space A2 that are in astep-like configuration. In addition, the outlet E2 is adjacent to theevaporation space A2, and the inlet E1 is adjacent to the supply spaceA1. As shown in FIG. 2, one end of the heat pipe 130 is in thermalcontact with the heat source 20, and the other end of the heat pipe 130is connected to an external part of the evaporator 110 and located belowthe second space A2. In this embodiment, an external part and aninternal part of the base 112 are consistently in a step-like structure.Namely, there is the same height difference ΔZ in the external part andthe internal part of the base 112. Thus, FIG. 5 only marks the heightdifference ΔZ for the external part. With the height difference, theheat pipe 130 is allowed to come into contact with a recessed structureof the external part of the evaporator 110.

Moreover, a gap ΔX is provided between the other end of the heat pipe130 and the external part of the evaporator 110 in the first space A1,so as to insulate heat to a certain extent. Namely, the heat transferredby the heat pipe 130 is able to be converged at the second space A2,thereby maintaining the working fluid F of the first space A1 to be inthe liquid phase. Furthermore, the heat conductive pillars 116 aredisposed in the second area A2, so as to increase a contact area withthe working fluid F. Accordingly, the working fluid F in the secondspace A2 is able to smoothly absorb heat and be transferred from theliquid phase to the vapor phase. In addition, due to a characteristic ofplateau of the second space A2 relative to the first space A1, theworking fluid F in vapor is unable to flow out from the inlet E1. Inaddition, the working fluid F that is not heated and is in a liquidphase fills the inlet E1 and the first space A1. Therefore, the workingfluid F in vapor is only discharged out of the evaporator 110 from theoutlet E2, whereas the working fluid F in liquid continuously flows fromthe first space A1 to the second space A2 to absorb heat. Sucharrangement effectively prevents the working fluid F in vapor fromflowing back and drives the working fluid F to flow in the loopaccording to the direction shown in the drawings.

FIG. 6 is a schematic partial view illustrating a heat dissipationmodule according to another embodiment of the invention. Here, the uppercover of the evaporator shown in FIG. 2 is omitted to illustratestructural features therein. Referring to FIG. 6, in this embodiment, anevaporator 310 of the heat dissipation module 300 includes a first sink312 and a second sink 314 located on a virtual plane P2. In addition, acavity space of the first sink 312 substantially has a portion B11 of afirst space (supply space) B1, and a cavity space of the second sink 314substantially includes another portion B12 of the first space (supplyspace) B1 and a second space (evaporation space) B2. In addition, thereis a height difference between the portion B12 and the second space B2along the Z-axis, showing a step-like configuration. A pipe assembly 320includes a first pipe member 321 and a second pipe member 322respectively connected between the first sink 312 and the second sink314. Specifically, the first pipe member 321 is connected between anoutlet of the first sink 312 and an inlet of the second sink 314, thesecond pipe member 322 is connected between an outlet of the second sink314 and an inlet of the first sink 312.

In other words, the working fluid F in liquid in this embodimentsubstantially flows from the first pipe member 321 to the second sink314 after flowing from the second pipe member 322 to the first sink 312.Consequently, the different portions B11 and B12 become the supply space(the first space B1) of the working fluid F in liquid that supplies theworking fluid F in liquid to the evaporation space (second space B2) toabsorb heat. Namely, the working fluid F in liquid fills the first pipemember 321 and the first space B1, so the portion B11 of the first spaceB1 in the first sink 312 may be considered as a front station (or abuffer space) that supplies the working fluid F in liquid to the portionB12 to ensure a sufficient amount of the working fluid F in liquid to bedriven to the portion B12 and the second space B2 (evaporation space).Accordingly, the working fluid F in vapor flows from the second space B2of the second sink 314 toward the second pipe member 322, whereas theworking fluid F in liquid flows from the second pipe member 322 to thefirst sink 312 (i.e., the portion B11), and flows to the portion B12 ofthe second sink 314 through the first pipe member 321.

In addition, the heat pipe 130 and the heat conductive pillars 116 ofthis embodiment are the same as those in the previous embodiments. Thus,details in this regard will not be repeated in the following.

FIG. 7 is a partial schematic cross-sectional view illustrating a heatdissipation module according to yet another embodiment of the invention.Referring to FIG. 7, differing from the previous embodiments where thestep-like structure exhibiting a height difference is in the second sink314, areas exhibiting a height difference are respectively disposed incorresponding sinks in this embodiment. Specifically, in a heatdissipation module 400 of this embodiment, an evaporator 410 includes afirst sink 412 and a second sink 414. In addition, the first sink 412has a supply space (a first space C1), whereas a second sink 414includes an evaporation space (a second space C2). A pipe assembly 420includes a first pipe member 421 and a second pipe member 422. Inaddition, the first pipe member 421 is connected between an outlet ofthe first sink 412 and an inlet of the second sink 414, and the secondpipe member 422 is connected between an outlet of the second sink 414and an inlet of the first sink 412. Here, only a part of the second pipemember 422 near the evaporator 410 is illustrated, and the rest isomitted. In addition, the first sink 412 and the second sink 414 arelocated on a virtual plane P3.

Accordingly, the second space C2 in the second sink 414 is anevaporation space with whole structure, whereas the first space C1 inthe first sink 412 is a storage space with whole structure. In addition,there is a height difference (shown as a height difference ΔZ1 betweenthe outlet of the first sink 412 and the inlet of the second sink 414here as an example) between the second space C2 and the first space C1along the Z-axis. Accordingly, in the flowing direction of the workingfluid F, the first pipe member 421 is inclined from low to high. Theworking fluid F in liquid fills the first space C1 and a position wherethe first pipe member 421 and the first sink 412 are connected. Sincethe first pipe member 421 is inclined, the working fluid F in vapor isstill unable to flow back to the first space C1. Also, with a forcedriving the working fluid F in vapor to flow from the first sink 412toward the second sink 414 through the second sink 414, the workingfluid F in vapor is still pushed back to the evaporation space (thesecond space C2) by the working fluid F in liquid. Thus, the workingfluid F in vapor is still discharged out of the evaporator 410 from theoutlet of the second sink 414, and consequently the working fluid Fstill flows uni-directionally. Besides, the heat pipe 130 and heatconductive pillars (not shown) of this embodiment are the same as thoseof the previous embodiments. Thus, details in this regard will not berepeated in the following.

FIGS. 8 and 9 are respectively exploded views illustrating an evaporatoraccording to still another embodiment of the invention. FIG. 10 is aperspective view illustrating the evaporator of FIGS. 8 and 9. FIG. 11is a cross-sectional view illustrating the evaporator of FIG. 10 alongan A-A′ line. Referring to FIGS. 8 to 11, in this embodiment, anevaporator 510 includes a case 512 and a block 514 disposed in the case512. In addition, the case 512 has an inlet E3 and an outlet E4. Theblock 514 is disposed in the case 512 to divide a cavity in the case 512into a first space D1 and a second space D2. The block 514 has a firstchannel F1 to connect the first space D1 and the second space D2. Inaddition, the case 512 is formed by combining an upper case 512 a and alower case 512 b through soldering or melting. The upper case 512 a hasthe inlet E3 and the outlet E4.

In addition, the upper case 512 a has a first recess R1, a second recessR2, and a third recess R3, and the second recess R2, the third recessR3, and the first recess R1 are arranged in sequence in a direction fromthe inlet E3 toward the outlet E4 (i.e., the flowing direction of theworking fluid F). The first recess R1 and the second recess R2 form atop wall of the cavity after the upper case 512 a and the lower case 512b are assembled. In addition, the third recess R3 is configured toaccommodate the block 514 and make the second recess R2 and the lowercase 512 b a portion of the first space D1. Moreover, the first recessR1 and the lower case 512 b form a portion of the second space D2. Theheat source of the electronic device (as described in the previousembodiments, such as the heat source 20 of FIG. 2) substantiallycorresponds to the second space D2 of the evaporator 510. Namely, theheat generated by the heat source may be transferred to the second spaceD2 via the heat pipe or through direct contact. In this way, the workingfluid F in liquid in the second space D2 may absorb heat and betransformed to become the working fluid in vapor and flow to the pipeassembly 120 (a portion of the pipe assembly is shown in FIG. 11, and acomplete illustration may be referred to the previous embodiments) fromthe outlet E4. The first channel F1 is adjacent to the lower case 512 band connects the first space D1 and the second space D2, such that theworking fluid F in liquid is able to flow from the first space D1 towardthe second space D2 to supplement the working fluid F undergoingtransformation in the second space D2.

Referring to FIG. 11, specifically, the heat dissipation module of thisembodiment further includes a capillary medium 540. In addition, aportion of the capillary medium 540 is disposed in the first space D1and the second space D2 and through the first channel F1, while anotherportion of the capillary medium 540 is extensively disposed in the firstspace D1 and the pipe assembly 120. In this embodiment, the capillarymedium 540 may be selected from a porous material, a powder metallurgymaterial, a porous sintered body, a porous foaming body, a porouscarbonized body, etc., and it shall be understood that the inventiondoes not intend to impose a limitation in this regard. In addition, thepowder metallurgy material or the porous sintered body may be selectedfrom silver, copper, aluminum alloy, or other suitable metal or alloymaterials.

Accordingly, after the heat of the heat source is transferred to thesecond space D2 to heat the working fluid F in liquid in the space andtransform the working fluid F in liquid into the working fluid F invapor, the presence of the capillary medium 540 allows the working fluidF in liquid in the first space D1 to, through absorption and guiding ofthe capillary medium 540, pass through the first channel F1 and betransferred to the second space D2. In this way, the working fluid F inthe second space D2 may continuously absorb heat and undergoestransformation. In addition, the working fluid F in liquid at the pipeassembly 120 may also be continuously transferred to the first space D1through the capillary medium 540. In this way, the working fluid F inliquid is able to be continuously supplied from the pipe assembly 120and the first space D1 to the second space D2. In addition, sucharrangement also provides a driving force to allow the working fluid Fto flow in the pipe assembly 120 and the first space D1 and the secondspace D2 of the evaporator 510.

In addition, as shown in FIG. 11, a height of the inlet E3 relative to abottom BL of the lower case 512 b is lower than a height of the outletE4 relative to the bottom BL of the lower case 512 b. Therefore, theworking fluid F in liquid is able to smoothly flow to the first space D1from the inlet E3, and the working fluid F in vapor is able to smoothlyflow out of the evaporator 510 from the second space D2. In other words,with a configuration on the heights of the inlet E3 and the outlet E4(relative to the bottom BL), the flowing direction of the working fluidF is able to be controlled effectively. Namely, the working fluid F inliquid flows into the evaporator 510 from the lower inlet E3, and theworking fluid F in vapor is discharged from the higher outlet E4, so asto meet a characteristic of single circulation of the working fluid F inthe closed loop and prevent the working fluid F in vapor from flowingback. Moreover, in this embodiment, a diameter of the inlet E3 issmaller than a diameter of the outlet E4. Such configuration alsoresults in a pressure difference in an internal space of the evaporator510, thereby facilitating circulation of the working fluid F in theloop.

In addition, referring to FIGS. 8 to 10, in this embodiment, the secondspace D2 (i.e., a space formed after the first recess R1 of the uppercase 512 a is combined with the lower case 512 b) is in a profilegradually convergent from the block 514 toward the outlet E4, so thatthe working fluid F in vapor in the second space D2 are converged anddirected toward the outlet E4. In addition, the block 514 further has asecond channel F2 adjacent to the upper case 512 a and connecting thefirst space D1 and the second space D2. In other words, the secondchannel F2 is located above the first channel F1. The second channel F2has a profile gradually convergent from the first space D1 toward thesecond space D2, so as to converge and guide the working fluid F invapor in the first space D1 toward the second space D2 and prevent theworking fluid F is vapor in the second space D2 from flowing back to thefirst space D1.

Referring to FIGS. 9 and 11 again, in this embodiment, the first recessR1 of the upper case 512 a has a first surface S1 facing the lower case512 b, and the second recess R2 has a second surface S2 facing the lowercase 512 b. In addition, the first surface S1 and the second surface S2are inclined with respect to the bottom BL of the lower case 512 b fromthe inlet E3 toward the outlet E4. As shown in FIG. 11, a side of thesecond surface S2 close to the inlet E3 is lower, whereas a side of thefirst surface S1 close to the outlet E4 is higher. Therefore, aconfiguration of heights corresponding to the inlet E3 and the outlet E4(i.e., a state where the right side is lower and the left side is higherin the figure) is shown. Accordingly, the space of the second space D2is larger than the space of the first space D1, so the second space D2is consequently able to accommodate more of the working fluid F invapor. In addition, due to an inclined arrangement of the first surfaceS1 and the second surface S2, an effect of movement of guiding theworking fluid F from the inlet E3 toward the outlet E4 is facilitated.

Besides, referring to FIGS. 8, 10, and 11, the evaporator 510 furtherincludes a plurality of heat conductive pillars 516 disposed on asurface of the lower case 512 b and located in the second space D2. Theheat conductive pillars 516 are divided into the heat conductive pillars516 of a third space A3 and the heat conductive pillars 516 of a fourthspace A4 based on locations of the heat conductive pillars 516 in thelower case 512 b. A profile of the heat conductive pillars 516 in thethird space A3 is consistent with a profile of an orthogonal projectionof the heat source (shown in FIG. 2) on the lower case 512 b (or theprofile of the heat conductive pillars 516 is consistent with a profileof an orthogonal projection of the heat pipe and a contact end of theevaporator 510 on the lower case 512 b), and the heat conductive pillars516 in the fourth space A4 are located between the block 514 and theheat conductive pillars 516 in the third space A3. In other words, theheat conductive pillars 516 that are divided may be considered as beingdivided into the heat conductive pillars 516 of a primary heating area(i.e., the third space A3) that directly corresponds to the heat sourceand the heat conductive pillars 516 of a secondary heating area (i.e.,the fourth space A4) that does not correspond to the heat source. Inaddition, structures of the heat conductive pillars 516 are configuredto absorb heat from the heat source and heat the working fluid F of thesecond space D2 accordingly.

Consequently, most of the working fluid F in vapor in the second spaceD2 may be generated by heating the working fluid F in liquid with theheat conductive pillars 516 in the third space A3. Since the conductivepillars 516 in the fourth space A4 do not directly correspond to theheat source, the working fluid F in vapor generated by heating theworking fluid F in liquid with the conductive pillars 516 in the fourthspace A4 is less than that generated with the heat conductive pillars516 in the third space A3. Accordingly, the working fluid F in vapor inthe primary heating area (the third space A3) may flow toward the outletE4 along the inclined first surface S1, and a pressure above the primaryheating area consequently becomes lower, thereby guiding the workingfluid F in vapor above the secondary heating area to move toward theprimary heating area. In the meantime, since the working fluid F invapor in the secondary heating area is not as much and robust as that inthe primary heating area, the working fluid F in vapor in the secondaryheating area is less easy to be filled into the block 514 having thesecond channel F2 and may thus be guided to the outlet E4 more easilydue to a lower pressure in the primary heating area, so that the workingfluid F in vapor in the evaporator 510 has a preferable uni-directionalcirculation.

It should also be noted that the block 514 of this embodiment is a badheat conductor. Thus, the heat generated by the heat source is absorbedonly in the second space D2 to prevent over-vaporization of the workingfluid F in liquid in the first space D1.

In view of the foregoing, in the embodiments of the invention, the loopof the heat dissipation module is formed by combining the evaporator andthe pipe assembly, and the working fluid is filled into the loop, sothat the heat is absorbed and dissipated through transformation of theworking fluid. In addition, the cavity of the evaporator is divided intodifferent spaces, such that the heat source only transfers heat to oneof the spaces through the heat pipe, whereas the working fluid inanother space remains in the liquid phase to be supplied to a heatabsorption space. Namely, the evaporator is substantially divided intothe evaporation space that absorbs heat and the buffer space storing theworking fluid in liquid, thereby ensuring that the working fluid inliquid required by the evaporator is continuously supplied. Here, inaddition to separating the cavity of the evaporator using the block, theevaporator may be substantially divided into two separate sinks, therebyhaving the evaporator divided into spaces.

In addition, with the capillary medium disposed at a condensing segmentof the pipe assembly and the evaporator, when the working fluid istransformed due to absorption of heat and is reduced, the working fluidin liquid may be provided to the space where heat is absorbed fromanother space through guiding of the condensing segment of the pipeassembly. Accordingly, the working fluid is able to smoothly flowcontinuously in the case and the pipe. Even if the heat dissipationassembly is disposed in a horizontal arrangement in accordance with theelectronic device, the circulation for heat dissipation may continuewithout being influenced by gravity.

Moreover, there is a difference in height between the spaces. Forexample, the evaporator or the inlet and the outlet of the pipe assemblyare provided with a path that has a difference in height for the workingfluid to pass through, such that the working fluid flows out of theevaporator uni-directionally when the working fluid absorbs heat and istransformed from the liquid phase into the vapor phase. Furthermore, theworking fluid in gas is prevented from flowing back due to the heightdifference. Therefore, the working fluid's characteristic of beingdriven uni-directionally in the loop is able to be maintainedeffectively.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of the presentinvention without departing from the scope or spirit of the invention.In view of the foregoing, it is intended that the present inventioncover modifications and variations of this invention provided they fallwithin the scope of the following claims and their equivalents.

What is claimed is:
 1. A heat dissipation module, comprising: anevaporator, having an internal space divided into a first space and asecond space different from each other; and a pipe assembly, assembledto the evaporator to form a loop, the loop filled with a working fluid,wherein the working fluid in liquid state receives heat in the secondspace and flows to the pipe assembly after being transformed into vaporstate, and the working fluid in vapor state flows into the first spaceafter being transformed into liquid state by dissipating heat in thepipe assembly, and is stored in the first space to be supplied to thesecond space, wherein the evaporator has an inlet and an outlet, andthere is a height difference between the first space and the secondspace, the second space being higher than the first space, and theoutlet being higher than the inlet; a heat pipe, wherein one end of theheat pipe receives heat, another end of the heat pipe is connected to anexternal part of the evaporator and faces the second space, and theanother end of the heat pipe contacts a recessed structure of theexternal part, wherein the external part of the evaporator and aninternal part of the evaporator are consistently in a step structure toform the recessed structure.
 2. The heat dissipation module as claimedin claim 1, wherein a step is provided between the first space and thesecond space, and the working fluid in liquid state fills the inlet toprevent the working fluid in vapor state from flowing back.
 3. The heatdissipation module as claimed in claim 1, wherein a gap is providedbetween the another end and the external part of the evaporator in thefirst space.
 4. The heat dissipation module as claimed in claim 1,further comprising: a heat dissipation plate, thermally contacting thepipe assembly, wherein the working fluid in vapor state flowing throughthe pipe assembly dissipates heat by means of the pipe assembly and theheat dissipation plate, so as to be transformed into the working fluidin liquid state and flow into the first space.
 5. The heat dissipationmodule as claimed in claim 1, further comprising a plurality of heatconductive pillars disposed in the second space.
 6. The heat dissipationmodule as claimed in claim 1, wherein a diameter of the inlet is smallerthan a diameter of the outlet.